1. Field of the Invention
This invention relates generally to tamper evident closures, and more particularly to a tamper evident closure of a container, the tamper evident closure having a closure overcap that functions to hold a dispensing spout of the container in the closed position, the tamper evident closure further having an upwardly extending cam that functions to facilitate removal of the closure overcap.
2. Description of Related Art
Most containers that contain consumables that are in the retail market today, including bottles and dispensers, contain a tamper evident closure that enables the purchasers of these products to determine if someone else has already opened and re-closed the container. The tamper evident devices used include a visible feature to immediately indicate that the container has been opened. Tamper evident features allow purchasers to have confidence in the product, assuring them that nobody has tampered with the container.
A closure for a sports bottle, or similar dispensing container, is typically screwed onto the bottle. The closure typically has a tamper evident ring surrounding the base of the closure which is connected to the closure by fragmentable webs. When the closure is assembled to the bottle, the tamper evident ring snaps over a corresponding ring formed on the neck of the bottle. When the cap is removed from the bottle by unscrewing, the tamper evident ring stays on the bottle neck. The unscrewing forces lift the cap away from the tamper evident ring, breaking the fragmentable webs. An example of such a closure is shown in Beck, U.S. Pat. No. 5,456,374. Functionally equivalent closures that use multiple cams instead of threads are shown in Heinlein, U.S. Pat. No. 4,501,373 and Boik, U.S. Pat. No. 4,560,076. Even when the cap is replaced, it is obvious and visible to the consumer that these webs have been broken and that the product has been tampered with. If the purchaser found the bottle on a retailer's shelf with broken webs, he or she would know that it is best to leave it alone.
Similar tamper evident bands having fragmentable webs are also used to attach an overcap to the closures described above. Examples of such overcaps are shown in Beck, U.S. Pat. Nos. 5,829,611 and 5,456,374. As described above, if the overcap has been removed or otherwise tampered with, the broken fragmentable webs leave a readily visible warning to the consumer.
One disadvantage to these prior art closures is that they require the user to break all of the fragmentable webs at substantially the same time when unscrewing or otherwise removing the closure or overcap. This limits the strength of the fragmentable webs, because if the fragmentable webs are too strong, the user will have difficulty removing the closure or overcap.
This is an important consideration, because it is desirable to connect the overcap to the closure with fragmentable webs that are as strong as possible to prevent accidental breakage of the fragmentable webs. In the case of containers that have a pouring spout that can be opened and closed, it is also desirable to provide an overcap that is strongly attached to prevent the accidental opening of the closure, such as if the container is dropped.
The most common dispensing closure for beverages use a push-pull arrangement, most commonly used in sports bottles, such as shown in Beck, U.S. Pat. Nos. 5,829,611 and 5,456,374. These closures require that the user pull a button up which opens the dispensing orifice so that the product can be dispensed, generally by squeezing on the bottle. Another type of dispensing closure is disclosed in Dark, U.S. Pat. Nos. 4,440,327 and 5,392,968, whereby a spout is integrally hinged and seals in the down position and dispenses when lifted to the vertical position. The Dark invention can also be dispensed by squeezing on the container.
One of the drawbacks of the dispensing closure is that when in the sealed position and pressure is applied to the container, the pressure inside the container can push on the inside of the dispensing closure forcing it open. It is therefore advantageous to have an overcap that shows tamper evidence and not only keeps the dispensing closure clean and also helps to hold the dispensing mechanism in the sealed position.
The prior art has grappled with the challenge of providing a fragmentable web that is strong enough to securely fasten the overcap to the closure. Wilde, U.S. Pat. No. 4,923,073, teaches a tamper evident cap having a oblique groove into which fits a shaped locking ring. Twisting the cap both lifts the threadedly engaged cap and causes the tamper evident web to fracture in a serial manner; however, the fragmentable webs still break at least two at a time, so the strength of the fragmentable webs is limited. Furthermore, the unusual oblique structure of the groove makes assembly more difficult.
Another approach taken by the prior art has been to provide a tamper evident band that is torn off by the user, thereby breaking the fragmentable webs one at a time. Examples of such structures are shown in Menke, U.S. Pat. No. 3,901,403, and Dutt et al., U.S. Pat. No. 5,085,333. This approach is undesirable because it is preferred that the tamper evident band remain fastened to the closure, both for the purposes of waste disposal and for the purpose of providing a visual indication that someone has tampered with the container.
The prior art teaches tamper evident bands that are connected to a container or closure with fragmentable webs. However, the prior art does not teach an overcap connected to a closure with a tamper evident band that is unusually strong, the closure being designed so that the fragmentable webs are broken one at a time using a single upwardly extending cam. The present invention fulfills these needs and provides further related advantages as described in the following summary.